src/gpu/GrAtlasTextBlob.cpp

/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrAtlasTextBlob.h"

void GrAtlasTextBlob::appendGlyph(int runIndex,
                                  const SkRect& positions,
                                  GrColor color,
                                  GrBatchTextStrike* strike,
                                  GrGlyph* glyph,
                                  GrFontScaler* scaler, const SkGlyph& skGlyph,
                                  SkScalar x, SkScalar y, SkScalar scale, bool applyVM) {

    // If the glyph is too large we fall back to paths
    if (glyph->fTooLargeForAtlas) {
        this->appendLargeGlyph(glyph, scaler, skGlyph, x, y, scale, applyVM);
        return;
    }

    Run& run = fRuns[runIndex];
    GrMaskFormat format = glyph->fMaskFormat;

    Run::SubRunInfo* subRun = &run.fSubRunInfo.back();
    if (run.fInitialized && subRun->maskFormat() != format) {
        subRun = &run.push_back();
        subRun->setStrike(strike);
    } else if (!run.fInitialized) {
        subRun->setStrike(strike);
    }

    run.fInitialized = true;

    size_t vertexStride = GetVertexStride(format);

    subRun->setMaskFormat(format);

    run.fVertexBounds.joinNonEmptyArg(positions);
    subRun->setColor(color);

    intptr_t vertex = reinterpret_cast<intptr_t>(this->fVertices + subRun->vertexEndIndex());

    if (kARGB_GrMaskFormat != glyph->fMaskFormat) {
        // V0
        SkPoint* position = reinterpret_cast<SkPoint*>(vertex);
        position->set(positions.fLeft, positions.fTop);
        SkColor* colorPtr = reinterpret_cast<SkColor*>(vertex + sizeof(SkPoint));
        *colorPtr = color;
        vertex += vertexStride;

        // V1
        position = reinterpret_cast<SkPoint*>(vertex);
        position->set(positions.fLeft, positions.fBottom);
        colorPtr = reinterpret_cast<SkColor*>(vertex + sizeof(SkPoint));
        *colorPtr = color;
        vertex += vertexStride;

        // V2
        position = reinterpret_cast<SkPoint*>(vertex);
        position->set(positions.fRight, positions.fBottom);
        colorPtr = reinterpret_cast<SkColor*>(vertex + sizeof(SkPoint));
        *colorPtr = color;
        vertex += vertexStride;

        // V3
        position = reinterpret_cast<SkPoint*>(vertex);
        position->set(positions.fRight, positions.fTop);
        colorPtr = reinterpret_cast<SkColor*>(vertex + sizeof(SkPoint));
        *colorPtr = color;
    } else {
        // V0
        SkPoint* position = reinterpret_cast<SkPoint*>(vertex);
        position->set(positions.fLeft, positions.fTop);
        vertex += vertexStride;

        // V1
        position = reinterpret_cast<SkPoint*>(vertex);
        position->set(positions.fLeft, positions.fBottom);
        vertex += vertexStride;

        // V2
        position = reinterpret_cast<SkPoint*>(vertex);
        position->set(positions.fRight, positions.fBottom);
        vertex += vertexStride;

        // V3
        position = reinterpret_cast<SkPoint*>(vertex);
        position->set(positions.fRight, positions.fTop);
    }
    subRun->appendVertices(vertexStride);
    fGlyphs[subRun->glyphEndIndex()] = glyph;
    subRun->glyphAppended();
}

void GrAtlasTextBlob::appendLargeGlyph(GrGlyph* glyph, GrFontScaler* scaler, const SkGlyph& skGlyph,
                                       SkScalar x, SkScalar y, SkScalar scale, bool applyVM) {
    if (nullptr == glyph->fPath) {
        const SkPath* glyphPath = scaler->getGlyphPath(skGlyph);
        if (!glyphPath) {
            return;
        }

        glyph->fPath = new SkPath(*glyphPath);
    }
    fBigGlyphs.push_back(GrAtlasTextBlob::BigGlyph(*glyph->fPath, x, y, scale, applyVM));
}

bool GrAtlasTextBlob::mustRegenerate(SkScalar* outTransX, SkScalar* outTransY,
                                     const SkPaint& paint,
                                     GrColor color, const SkMaskFilter::BlurRec& blurRec,
                                     const SkMatrix& viewMatrix, SkScalar x, SkScalar y) {
    // If we have LCD text then our canonical color will be set to transparent, in this case we have
    // to regenerate the blob on any color change
    // We use the grPaint to get any color filter effects
    if (fKey.fCanonicalColor == SK_ColorTRANSPARENT &&
        fPaintColor != color) {
        return true;
    }

    if (fViewMatrix.hasPerspective() != viewMatrix.hasPerspective()) {
        return true;
    }

    if (fViewMatrix.hasPerspective() && !fViewMatrix.cheapEqualTo(viewMatrix)) {
        return true;
    }

    // We only cache one masked version
    if (fKey.fHasBlur &&
        (fBlurRec.fSigma != blurRec.fSigma ||
         fBlurRec.fStyle != blurRec.fStyle ||
         fBlurRec.fQuality != blurRec.fQuality)) {
        return true;
    }

    // Similarly, we only cache one version for each style
    if (fKey.fStyle != SkPaint::kFill_Style &&
        (fStrokeInfo.fFrameWidth != paint.getStrokeWidth() ||
         fStrokeInfo.fMiterLimit != paint.getStrokeMiter() ||
         fStrokeInfo.fJoin != paint.getStrokeJoin())) {
        return true;
    }

    // Mixed blobs must be regenerated.  We could probably figure out a way to do integer scrolls
    // for mixed blobs if this becomes an issue.
    if (this->hasBitmap() && this->hasDistanceField()) {
        // Identical viewmatrices and we can reuse in all cases
        if (fViewMatrix.cheapEqualTo(viewMatrix) && x == fX && y == fY) {
            return false;
        }
        return true;
    }

    if (this->hasBitmap()) {
        if (fViewMatrix.getScaleX() != viewMatrix.getScaleX() ||
            fViewMatrix.getScaleY() != viewMatrix.getScaleY() ||
            fViewMatrix.getSkewX() != viewMatrix.getSkewX() ||
            fViewMatrix.getSkewY() != viewMatrix.getSkewY()) {
            return true;
        }

        // We can update the positions in the cachedtextblobs without regenerating the whole blob,
        // but only for integer translations.
        // This cool bit of math will determine the necessary translation to apply to the already
        // generated vertex coordinates to move them to the correct position
        SkScalar transX = viewMatrix.getTranslateX() +
                          viewMatrix.getScaleX() * (x - fX) +
                          viewMatrix.getSkewX() * (y - fY) -
                          fViewMatrix.getTranslateX();
        SkScalar transY = viewMatrix.getTranslateY() +
                          viewMatrix.getSkewY() * (x - fX) +
                          viewMatrix.getScaleY() * (y - fY) -
                          fViewMatrix.getTranslateY();
        if (!SkScalarIsInt(transX) || !SkScalarIsInt(transY) ) {
            return true;
        }

        (*outTransX) = transX;
        (*outTransY) = transY;
    } else if (this->hasDistanceField()) {
        // A scale outside of [blob.fMaxMinScale, blob.fMinMaxScale] would result in a different
        // distance field being generated, so we have to regenerate in those cases
        SkScalar newMaxScale = viewMatrix.getMaxScale();
        SkScalar oldMaxScale = fViewMatrix.getMaxScale();
        SkScalar scaleAdjust = newMaxScale / oldMaxScale;
        if (scaleAdjust < fMaxMinScale || scaleAdjust > fMinMaxScale) {
            return true;
        }

        (*outTransX) = x - fX;
        (*outTransY) = y - fY;
    }


    // If we can reuse the blob, then make sure we update the blob's viewmatrix, and x/y
    // offsets.  Note, we offset the vertex bounds right before flushing
    fViewMatrix = viewMatrix;
    fX = x;
    fY = y;

    // It is possible that a blob has neither distanceField nor bitmaptext.  This is in the case
    // when all of the runs inside the blob are drawn as paths.  In this case, we always regenerate
    // the blob anyways at flush time, so no need to regenerate explicitly
    return false;
}

// TODO get this code building again
#ifdef CACHE_SANITY_CHECK
void GrAtlasTextBlob::AssertEqual(const GrAtlasTextBlob& l, const GrAtlasTextBlob& r) {
    SkASSERT(l.fSize == r.fSize);
    SkASSERT(l.fPool == r.fPool);

    SkASSERT(l.fBlurRec.fSigma == r.fBlurRec.fSigma);
    SkASSERT(l.fBlurRec.fStyle == r.fBlurRec.fStyle);
    SkASSERT(l.fBlurRec.fQuality == r.fBlurRec.fQuality);

    SkASSERT(l.fStrokeInfo.fFrameWidth == r.fStrokeInfo.fFrameWidth);
    SkASSERT(l.fStrokeInfo.fMiterLimit == r.fStrokeInfo.fMiterLimit);
    SkASSERT(l.fStrokeInfo.fJoin == r.fStrokeInfo.fJoin);

    SkASSERT(l.fBigGlyphs.count() == r.fBigGlyphs.count());
    for (int i = 0; i < l.fBigGlyphs.count(); i++) {
        const BigGlyph& lBigGlyph = l.fBigGlyphs[i];
        const BigGlyph& rBigGlyph = r.fBigGlyphs[i];

        SkASSERT(lBigGlyph.fPath == rBigGlyph.fPath);
        // We can't assert that these have the same translations
    }

    SkASSERT(l.fKey == r.fKey);
    SkASSERT(l.fViewMatrix.cheapEqualTo(r.fViewMatrix));
    SkASSERT(l.fPaintColor == r.fPaintColor);
    SkASSERT(l.fMaxMinScale == r.fMaxMinScale);
    SkASSERT(l.fMinMaxScale == r.fMinMaxScale);
    SkASSERT(l.fTextType == r.fTextType);

    SkASSERT(l.fRunCount == r.fRunCount);
    for (int i = 0; i < l.fRunCount; i++) {
        const Run& lRun = l.fRuns[i];
        const Run& rRun = r.fRuns[i];

        if (lRun.fStrike.get()) {
            SkASSERT(rRun.fStrike.get());
            SkASSERT(GrBatchTextStrike::GetKey(*lRun.fStrike) ==
                     GrBatchTextStrike::GetKey(*rRun.fStrike));

        } else {
            SkASSERT(!rRun.fStrike.get());
        }

        if (lRun.fTypeface.get()) {
            SkASSERT(rRun.fTypeface.get());
            SkASSERT(SkTypeface::Equal(lRun.fTypeface, rRun.fTypeface));
        } else {
            SkASSERT(!rRun.fTypeface.get());
        }

        // We offset bounds right before flush time so they will not be correct here
        //SkASSERT(lRun.fVertexBounds == rRun.fVertexBounds);

        SkASSERT(lRun.fDescriptor.getDesc());
        SkASSERT(rRun.fDescriptor.getDesc());
        SkASSERT(lRun.fDescriptor.getDesc()->equals(*rRun.fDescriptor.getDesc()));

        if (lRun.fOverrideDescriptor.get()) {
            SkASSERT(lRun.fOverrideDescriptor->getDesc());
            SkASSERT(rRun.fOverrideDescriptor.get() && rRun.fOverrideDescriptor->getDesc());;
            SkASSERT(lRun.fOverrideDescriptor->getDesc()->equals(
                    *rRun.fOverrideDescriptor->getDesc()));
        } else {
            SkASSERT(!rRun.fOverrideDescriptor.get());
        }

        // color can be changed
        //SkASSERT(lRun.fColor == rRun.fColor);
        SkASSERT(lRun.fInitialized == rRun.fInitialized);
        SkASSERT(lRun.fDrawAsPaths == rRun.fDrawAsPaths);

        SkASSERT(lRun.fSubRunInfo.count() == rRun.fSubRunInfo.count());
        for(int j = 0; j < lRun.fSubRunInfo.count(); j++) {
            const Run::SubRunInfo& lSubRun = lRun.fSubRunInfo[j];
            const Run::SubRunInfo& rSubRun = rRun.fSubRunInfo[j];

            SkASSERT(lSubRun.fVertexStartIndex == rSubRun.fVertexStartIndex);
            SkASSERT(lSubRun.fVertexEndIndex == rSubRun.fVertexEndIndex);
            SkASSERT(lSubRun.fGlyphStartIndex == rSubRun.fGlyphStartIndex);
            SkASSERT(lSubRun.fGlyphEndIndex == rSubRun.fGlyphEndIndex);
            SkASSERT(lSubRun.fTextRatio == rSubRun.fTextRatio);
            SkASSERT(lSubRun.fMaskFormat == rSubRun.fMaskFormat);
            SkASSERT(lSubRun.fDrawAsDistanceFields == rSubRun.fDrawAsDistanceFields);
            SkASSERT(lSubRun.fUseLCDText == rSubRun.fUseLCDText);

            //We can't compare the bulk use tokens with this method
            /*
            SkASSERT(lSubRun.fBulkUseToken.fPlotsToUpdate.count() ==
                     rSubRun.fBulkUseToken.fPlotsToUpdate.count());
            SkASSERT(lSubRun.fBulkUseToken.fPlotAlreadyUpdated ==
                     rSubRun.fBulkUseToken.fPlotAlreadyUpdated);
            for (int k = 0; k < lSubRun.fBulkUseToken.fPlotsToUpdate.count(); k++) {
                SkASSERT(lSubRun.fBulkUseToken.fPlotsToUpdate[k] ==
                         rSubRun.fBulkUseToken.fPlotsToUpdate[k]);
            }*/
        }
    }
}

#endif